Electric circuit extension connecter



May 1, 1934.

c. A. G'oon 1,956,949

ELECTRIC CIRCUIT EXTENSION CONNECTER Filed July 4, 1951 INI/EN TOR.CHARLES A. sooo BY MM ATTORNEY.

Patented May 1, 1934 PATENT orifice ELECTRC CIRCUIT EXTENSION CONNECTERyCharles A. Good, Oakland, Calif.

Application July 4, i931, Serial No. 548,718

8 Claims.

'The invention relates to improvements in connections for electriccircuit extensions or what is generally known as attachment plugs, andrelates more particularly in the present embodiment of the invention toheavy duty connecters designed for use in making portable extensions ofthe higher voltage or power circuits.

An object of the invention is to provide a connecter of the characterdescribed in which all portions of the cooperating engaging surfaces ofthe electrical contact elements will be simultaneously and sharplybrought into substantially full and complete contactual engagement onthe initial engagement of the elements whereby the possibility of arcingwill be greatly minimized.

Another object of the invention is to provide a connecter of thecharacter described in which will be eliminated any possibility ofestablishing electrical contact by slow motion or of reestablishingelectrical contact when the previous breaking of the circuit has beeneffected without effecting a substantially complete detachment of theconnecter members.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth in the followingdescription of the preferred form of the invention which is illustratedin the drawing accompanying and forming part of the specication. It isto be understood, however, that variations in the showing made by thesaid drawing and description may be adopted within the scope of theinvention as set forth in the claims.

Referring to said drawing:

Figure l is a longitudinal sectional view partly in elevation, of theconnecter with the connecting members in detached relation.

Figure 2 is a longitudinal sectional view of the upper half of theconnecter with the members positioned preparatory to effecting operativeengagement.

Figure 3 is a view similar to Figure 2, but the members are in fullyoperative engagement.

As illustrated in the drawing, the connecter ci my invention comprises apair of cooperating members 2 and 3 having a body of insulation materialand respectively provided with electric contact elements 4 and 5. Theelements 4 as here shown are stationary in the member 2, while theelements 5 are mounted in the member 3 for transverse movement therein.Preferably the elements 5 are pivotally connected to the meinber bymeans of pins 7 and are disposed in longitudinally extending openings 8.Springs 9 are positioned in the openings and arranged to engage theelements 5 so as to normally retain them in a transversely outwardposition. 'Ihe connecter as illustrated is designed for use withpolyphase current and for this reason the respective members areprovided with a plurality of the contacts. Each of the contacts isprovided with terminals 1l, to which the electrical conductors (notshown) may be secured, the conductors for the member 3 being extendedinto the openings 8, whereas the conductors for the member 2 areinserted into openings l2 of the latter in which the elements 5 arearranged to engage when the members are in engaged relation.

As will be understood, establishment of electrical connection betweenthe conductors associated with the different members is eiected bycontact of the elements when the members are in engaged relation. In thedesigns of connecters heretofore made, contact of the elements isusually effected by moving one of the connecter members into engagementwith the other whereby one element will slide longitudinally over theother and thereby resiliently engage same in overlapping relation. Suchan operation, it will be seen, entails an initial engagement of theelements with a minimum surface of the elements in contact, and it is toa large extent due to such form of initial contact that the dangerousarcing commonly prevalent in connecters is caused. It is therefore oneof the main objects of my invention to provide a means of contactbetween the elements which will result in a practically non-arcing aswell as an efiicient engagement of the elements. In general I accomplishthe foregoing by providing means which will serve to hold the movablecontact element in spaced relation to the cooperating element during themovement of the connecter members together until the elements aredisposed in substantially fully overlapping relation or in other wordswhen the cooperating engaging parts of the contact elements are intransverse opposed relation. In the present embodiment of the inventionsuch means is in the form of a relatively movable part provided on theconnecter member 3, and as illustrated comprises a sleeve 14telescopically mounted on the contact end of the member and having itsopen end l5 arranged for the reception of the contact end of member 2.The sleeve is limited in its loutward and inward movement by means of astop 16 which is secured to the member 3 and engages in a slot 17provided in the sleeve. Formed in the sleeve is a partition 18 having aplurality of openings 19 through which the elements 5 are arranged toextend. The elements as Will be clear from Figure 1 are pressed by thesprings 9 into substantial engagement with the outer side wall 21 of theopenings when the sleeve is in retracted position and the membersdisengaged. Formed in the elements 5 and located immediately forward ofthe portion 22 engaging the wall 21 when the sleeve is retracted asaforesaid, is an outwardly oiset portion 23 whereby on the extension ofthe sleeve the Wall 21 will engage the portion 23 and thereby force thecontacts transversely inward as indicated in Figure 2, the inwarddisplacement being of such extent that when the member 2 is insertedinto the sleeve, the contacts 5 will be disposed transversely inwardlyof and in spaced relation to the contacts 4, or in other words theelements will overlap each other Without being in contact. With theelements thus disposed, movement of the members together will serve toretract the sleeve whereby the wall 21 lwill become disengaged from theoffset 23 and the elements 5 will move into substantially full andcomplete contact with the elements 4, it being noted that the engagingmovement of the element will be eiected sharply due to the acute slopeof the portion 24 which joins the element portions 22 and 23. As will beclear from Figure 3, when the members are in operative engagement, eachelement 5 will be spaced from the wall 21 so that the full force of thesprings 9 will be exerted to maintain the cooperating elements incontact. It will be noted that the coengaging surfaces of the elements 4and 5 are correspondingly formed concave and convex respectively, sothat the proper initial seating of the elements as Well as the retentionof elements in seated position on the operative positioning of theconnecter members will be assured.

To break contact between the elements, the connecter members are pulledapart whereby the elements 5 will slide off the contacts 4, the sleevein the present case remaining in retracted position owing to the factthat greater resistance is met in depressing the contacts 5 by means ofthe sleeve than with the contacts 14. In this manner when the elementsbecome disengaged, the elements 5 will move transversely outwardly andany attempt to reestablish contact by moving the members togetherwithout rst having effected substantially complete detachment of themembers will result in bringing the outer end 26 of the elements 5against the sharply-curved insulated extension 27 of the contacts 4,thereby making it practically impossible to effect electrical contact. twill thus be seen that contact between the elements can only be madeupon depression of the elements 5 by the sleeve. An advantage of thecurved or angular portion 27 is that on disengagement of the contacts,the pressure of element 5 against such portion serves to urge themembers apart and thereby speed up the contact disengaging movement.With the breaking movement of the contacts thus quickcned it will beclear that the time the receding contacts are within arcing distance ofeach other and the resultant arcing that may occur is materiallyreduced.

It will be noted that during the entire operation of both making andbreaking contact, the sleeve completely closes the open or contact endsof the members so that any arcing that might be produced during suchoperations will be confined to the interior of the connecter.

In recapitulation, the operation of the connecter is as follows:Assuming that the members are detached from each other and an electricalconnection is desired, the member 2 is inserted into the sleeve afterthe latter has been moved to its extended position so as to depress thecontacts. The members are then pressed together whereby the contacts 5will be brought into overlapping spaced relation and then intocontactual engagement with the members 4. Breaking of the connection maythereafter be eiected by simply pulling the connecter members apart.

I claim:

1. In an electrical connecter, cooperating connecter members movableinto and out of engagement With each other, cooperating contact elementson the members, spring means auxiliary to and resiliently resistingdisplacement of one of said elements, and insulation means operative onmoving the members into engagement for successively displacing saidlatter element and releasing it for engagement with the other element.

2. In an electrical connecter, separable connecting members, a contactelement on one of said members, a contact element on the other member,insulation means on one of said members arranged to engage and laterallydisplace one of said elements whereby upon movement of said memberstogether said elements will be moved into spaced overlapping relation,and means for rendering said rst means inoperable upon movement of saidmembers together thereby affording a transverse movement of saidelements into contactual engagement with each other.

3. In an electrical connecter, cooperating engageable connecter members,a contact element on one member, a movable contact element on the othermember, a spring associated with said latter element arranged for urgingsame in engagement with said first element, and means insulated fromsaid elements operating against the action of said spring to hold saidsecond element out of operative relation to said rst element while saidmembers are being engaged for operation, and arranged to release saidsecond element on the substantial completion of said engagement wherebysaid second element will be free to move into engagement with said rstelement under the action of the spring.

4. In an electrical connecter, cooperating separable connecting members,contact elements on said members, means arranged to retain the membersin connectedengagement while the elements are being drawn into orwithdrawn out of contact, one of said members being provided with arecess portion adjacent the end of the element thereon and spring meansoperable on disconnection of said elements to move the element on theother member into said recess to prevent reengagement of the elementswhen the latter have been withdrawn from contact unless substantiallycomplete disengagement of said members shall have been iirst eiiected.

5. In an electrical connecter, separable connecter members, a Contactelement on one of said members, a displaceable contact element on theother of said members and resiliently resisting displacement from anormal position, and a sleeve carried by said last member, connectingmeans between said displaceable element and sleeve operative on movementof the latter relative to said last named member to move said secondcontact into spaced overlapping relation relative to said rst elementand to release said second element for engagement with the first elementon movementJ of said rst member and the sleeve relative to the secondmember.

6, In an electrical connecter, separable connecter members, a contact onone of said members, a displaceable contact on the other of said membersresiliently resisting displacement from a normal inoperative position,and a sleeve carried on said last named member, connection means betweensaid displaceable contact arranged upon outward movement of the latterrelative to said last member to place said second contact into spacedoverlapping relation relative to the rst contact, and operative to eiectengagement of the contacts upon inward movement of the sleeve and thesecond member relative to the rst member, said sleeve arranged toenclose the cooperating adjacent parts of the members when the contactsare being moved into or out of operative engagement.

7. In an electrical connecter, separable connecter members, anelectrical contact element on each of said members, means insulated fromsaid elements carried by one of said members arranged to engage andlaterally displace one of said elements whereby upon attachment of saidmembers said elements will be disposed in spaced overlapping relation,said means being arranged upon movement of said elements into said lastnamed position to release said displaced element for engagement withsaid other element.

8. An electrical connecter comprising separable body sections, a contactelement carried by one of said sections, said last named section beingprovided with a sharply inclined recess portion in laterally offsetrelation to an end of said element, a contact element on the othersection arranged on attachment of said sections to engage said rstelement, and a spring urging said second contact element in engagementwith the rst element when the sections are attached and operative upon.separation of said sections and the drawing of the elements fromengagement and at the instant of disengagement of the elements toquickly move said second contact into said recess portion.

CHARLES A. GOOD.

